The present invention relates generally to the shaping or compacting of granular masses, and more particularly to a method of producing coherent bodies from granular masses by subjecting the same to vibratory stresses requisite for compacting the granular masses into a coherent body.
There are many applications where it is necessary to compact granular materials into a coherent body of predetermined shape, the body being required to have certain characteristics, namely homogeneity and uniform density. It is possible in this manner to produce rather large bodies, and the invention is in particular concerned with the production of electrodes such as are, for instance, used in the smelting of aluminum. Such electrodes may reach weights of 1 ton or more and must have certain well-defined characteristics.
The materials of which these electrodes are made are of sand-like granular consistency and of a viscous flowable character; they do not, however, have a plastic character. Such materials are for instance discussed in U.S. Pat. No. 3,526,686 which is also concerned with the production of smelting electrodes.
To produce coherent shaped bodies, that is for instance electrodes, from such granular materials or masses is already known, for instance from the aforementioned U.S. Patent. It is proposed to confine a quantity of the granular mass in a mold which is supported on a vibratory platform and to vibrate the platform and thereby the mold to the extent requisite for obtaining the compaction necessary to transform the granular mass into a coherent body. A weight member is introduced through an open top of the mold and so that it rests on the granular mass accommodated in the mold in order to provide pressure upon the granular mass while the same is subjected to vibration. This vibration may be transmitted to the mold by rotating imbalanced masses.